Joined on December 20, 2004
Last Post on March 9, 2014
@ February 9, 2013 12:36 AM in Duty of the HVAC technician according to law?Per NFPA 211, 2010 ed., Table 220.127.116.11 for oil, solid fuel-burning appliances, domestic-type incinerators, and gas appliances other than Cat. I appliances.
@ February 8, 2013 9:22 AM in Flame inside burner tubeAs Timmie said, flashback is a function of too much primary air, too low manifold pressure or I would add high port loading or mechanical defects impeding the natural flow of mixed gas to the burner ports. Often, a subtle mis-alignment in the burners or how they are engaged with the burner orifice spud can do it. Gauge the burner orifice to ensure it is spec. Sometimes on LP, this can happen with the burner tilted uphill. Perform combustion analysis and look into each burner while firing. Try switching burner tubes to see if it is the tube or the position. Make sure there are no vent restrictions in the HX or common vent and you have proper draft--too high or too low are problems. Lastly, when in doubt, measure the manifold pressure directly off the valve downstream before the burner where possible. You need to ascertain if this is due to an increase in flame speed vs. a mechanical defect.
@ February 7, 2013 8:10 PM in check valveYou will find that in the applicable plumbing code but it is also an EPA reg. that your local water board can and will enforce. Need isolation valves to test and service. As stated, double check with atmospheric vent. If you install a bypass around an automatic feed valve for fast refilling such as after equipment replacement, the bypass must also be backflow protected.
@ February 7, 2013 8:05 PM in CSD-1 applicability questionAs i read it, you must has a lockable d/c at the appliance plus the emergency d/c either immediately outside the CAZ or just inside the door if it opens to the outside. one d/c per door.
If the d/c kills the power OR the fuel, it is ok.
Yep, looks to be all safeties on the other side of the system only. That mean a trip would kill all the power to the unit.
2009 IRC Table E4101.2 lists the disconnecting means per the appliance application. >1/8HP motor requires lockout d/c within sight of the equipment.
The 2009 IRC references CSD-1 and the ASME Boiler and Pressure Vessel Code Sections I and IV. Anyone have a copy of this Code?
@ February 2, 2013 5:41 PM in Duty of the HVAC technician according to law?http://www.nfpa.org/AboutTheCodes/AboutTheCodes.asp?DocNum=85
Here is an example of how NFPA tries to help a little bit. You can read their stds. online for free but they have done an excellent job of protecting them so you cannot print or save them. At least it gives you access to the current version online. Then you can decide if you need to purchase it or not. Good for the occasional peek.
One way to get the I-codes for residential is to join the ICC then choose the IRC for your choice of one free code book. You can become a voting member and get a code book for $20 less than the code book alone. Note that many codes such as NFPA and ICC are now including notations on sections that changed from the previous edition. That gives you 6 yrs. of coverage: 3 fwd and 3 looking back. One valuable benefit of joining the NFPA and ICC is access for technical support and opinions. This has easily paid for the membership a number of times. Nothing like a letter from Ted Lemoff on a gas code issue to quiet the most arrogant AHJ.
@ February 2, 2013 1:35 PM in Duty of the HVAC technician according to law?Tim hit on what I think is the biggest stumbling block which is the aggregate cost of all the codes, stds. and regs we are held accountbable to by law. Most UL and ANSI stds. run btw $700-900 each. Most codes and stds .get revised every 3 yrs. Now, add to that the ASHRAE Handbooks, ACCA manuals, etc. and it really adds up. Want more fun? Throw in the National Roofing Contractors Assn. Manual set of 4 at $650 just in case you have to mess with roofing systems; http://www.nrca.net/rp/pubstore/details.aspx?id=1125&c=4
There was a lawsuit about 10 yrs ago where the Southern Bldg. Code Congress sued over someone publishing their entire code online for free. They prevailed over the SBCCCI because the court found the public and contractors must have "reasonable" access to the rules they are held to. Not sure why this hasn't spilled over to all the codes. I don't have a problem paying for printing cost plus a reasonable profit but most of these are out of touch for the average guy. http://www.thefreelibrary.com/Court+overturns+ruling+in+SBCCI+case.+%28Headlines%29.-a091533691
@ January 31, 2013 2:24 PM in Sidewall ventingJim is essentially correct with one caveat: if a mfr. of an appliance specifically forbids sidewall power venting, then no. Otherwise, there is a "transfer of liability" or an "assumption of risk" on the part of the power vent mfr.. Regardless, a few rules: the power vent must incorporate a pressure switch that proves a pressure change signifying supposed sufficient air flow. This is not bulletproof but is considered an acceptable safety control. The powerventer must be interlocked. Basically, on a call for heat, it pre-purges, senses sufficient negative pressure, closes the contact to the furnace controls and allows the normal sequence of operation to continue. Should be vent become blocked, loss of power, or thermostat satisfied, the fan de-energizes, vent pressure equalizes causing the pressure switch to open causing the furnace to shut off. Now, some can incorporate a post purge cycle, which is desirable to mitigate condensation.
You still must maintain stated clearances to combustibles on vent pipe unless specifically tested as listed as a system. Same with vent sizing, unless engineered system accepted by the AHJ. Check local codes for vent termination restrictions over and above national codes and the product listing. The most restrictive requirements apply such as height above snow line.
@ January 28, 2013 6:34 PM in Duty of the HVAC technician according to law?The HVAC technician is burdened with so many layers of laws, standards, regulations, and instructions it is bewildering. I figured I'd start a thread just to get some dialogue going:
In a State where you have building codes, those codes are the LAW. They are not suggestions or Best Practices. They are what you will be held to in a court of law should there be a loss with damages/ injuries. Now, a municipal building official is a Code Enforcer--not a Code Legislator (I'll wait for the laughter to subside). There is a legal mechanism to change local codes. Once the State has adopted a code, the local municipalities may or may not be allowed to accept it depending upon your State laws. For instance, the Statutes in Pa. allow municipalities to "opt out" of the Pa Uniform Building Code, which is essentially the 2009 ICC code suite. Therefore, when you work in each of the various 1,347 or so jurisdictions within the Commonwealth, you need to know if they adopted the Pa UBC/ IRC or kept the old BOCA codes. Regardless of what an inspector tells you, you are held to that code that was voted into law. He legally does not have the power to willy nilly change the code to suite his purposes. In order to change a local code (ordinance), you must submit the request to the governing body with substantial documentation on why this change is relevant and necessary, what the drawbacks are, economic burden, inspection and enforcement ramifications, etc. Once the Council has voted to proceed, you need three public hearings so stakeholders and the public can comment. If adopted, then and only then does it become an enforceable law.
Now, within that code are references to various other codes, standards, regulations, etc. By Statute, you are held to those standards the same and the full body of the code. For example: You go to replace an oil fired boiler with a gas fired one. Do you have any obligation to inspect or reline the chimney and if so by what authority? The IRC says for gas appliances, refer to NFPA 211 for what constitutes an acceptable masonry chimney. Now, the IRC details in Ch 10 how to build a masonry chimney and fireplace and that is not as restrictive as 211. So, which do you refer to? 211. It is specified in G2427.5.2 specifically. Moreover, it is also almost universally referred to in all installation manuals. So, what does 211 say? Well, that's a whole week long inspection cert. course but suffice it to say no existing masonry heater flue can pass a Level II inspection per Ch14 of NFPA 211 without a listed liner. So, you will have to reline.
What about an oil fired boiler installation? Well, the IRC refers you to NFPA 211 for the chimney, NFPA 31 for the general oil burner requirements and ASME CSD-1 for the boiler installation.
What about using listed factory built chimney or venting? The IRC simply states to refer to the listed instructions of that vent mfr. What if the listing calls for a clearances less than that typically stated in the code? Those clearances in the code are intended for unlisted appliances or when the listed instructions cannot be located. However, if a mfr. has tested and listed their product at a reduced clearance, then you may go with the listed spec.. Listings trump codes. Codes are general rules for the absence of engineered, tested, listed appliances and products.
That ought to stir some discussion. Enjoy!
@ January 27, 2013 12:15 AM in ModCon Icing on ChimneyThat ss chimney cap is not an approved termination for any condensing gas appliance I'm aware of. Technically, it could be treated as a "shroud", which would require it to be listed with that appliance. This is a ForeverCap, which has a high static pressure compared to most other designs. NFPA 211 calls for a net free area 4x the area of the flue but that is for "chimneys". This std. does not consider placing a chimney cap over a condensing gas furnace flue gas outlet. Functionally, one can see where the ice is partially blocking the mesh on this cap further increasing the static pressure or making it harder to exhaust out of it. This cap is made of 304 stainless steel and will rot out from the acidic flue gases. Since PVC is not listed in the US (in Canada they have the S636 std.) there is no listed termination. Therefore, the code refers you to the listed instructions of the appliance. This plastic pipe would need a flashing so a water tight seal is made to keep water out of the flue. Much of the condensate that is not freezing is a dilute solution of carbonic and other acids. Acids generally do not freeze until supercooled. The do eat up the alkaline masonry. The acid can draw water from the interior of the brick to the face where the osmotic pressure can spall brick. Over time, the acid can eat away the hard fired face of the brick thus making it more porous and making it prone to freeze-thaw damage.
@ January 24, 2013 9:12 PM in ModCon Icing on ChimneyWhat is this mod-con venting into? Is there pvc, stainless steel liner or just flue tile?
@ January 21, 2013 1:02 PM in steam boiler conversion from Oil to Natural Gas?You will need an NFPA 211- Level II chimney inspection to ensure the suitability of this chimney for this use. If not properly lined or deteriorated, it will require a properly sized and type chimney liner.
@ January 21, 2013 12:55 PM in Should the low water cut-off be installed horizontally?That foil tape needs to come off the vent connector. Even though it carries a UL 181 listing, it is approved for warm air ducts and not vent/ chimney connectors. More specifically, it is prohibited by NFPA 211 because it conceals the condition of the pipe. If you think you need to seal the crimped joints, use furnace cement but since this is negative pressure venting, this should be unnecessary.
If the boiler mfr. does not specify a minimum water level then you can place the LWCO anywhere above the boiler you like. This is a little higher than typically found but doesn't hurt.
When you drop the water in the boiler to replace the pressure relief valve every 3 yrs you can remove the LWCO and service the probe unless the mfr. requires a more frequent schedule.
@ January 16, 2013 2:15 PM in Water heater causes nearby spray can to explode?Location, location, location. If the can was close up to raise the surface temp. on the can above 120F then yes it could have led to a rupture of the can. The question is, what part of a properly installed and operating WH gets that hot? Well, for one, on a gas WH, a single walled vent connector has a 6" clearance to combustibles. If there was a chimney blockage or other venting failure then yes, sufficient heat may have spilled out in an abnormal way. Regardless, it should be inspected by a professional.
@ January 14, 2013 2:25 PM in venting to longThe boiler must be installed in accordance with the listed instructions. If the max. horizontal vent run is 50LF (per brochure), then you have to move the boiler regardless of venting material.
Now, It appears this boiler has been approved for venting with PVC if you use their kit. I would recommend you look into polypropylene venting instead, which can take higher temps. and is listed to UL 1738.
If the AL29-4c stainless steel is rotting out then what about the appliance? Has it been inspected? what do you have to trap and manage condensate?
@ January 14, 2013 10:05 AM in Cause of CO poisoning unknownWho you gonna call? I mean when you have a local incident with bodies being taken out of buildings, either to the hospital or meat locker, who do you call?
Let's say your local fire captain is aware of an NCI certified professional and has his number. Who's going to pay this contractor? The building owner is probably scared out of his mind and figures ANYONE investigating his incident is just there to hang him so he's not going to open his wallet. A licensed Cause and Origin Fire Investigator is almost always hired by the attorney representing the defendant's insurance company, who probably is not even aware of the incident yet. The municipal inspectors are clueless because the incident probably would not have happened if they knew and did their jobs but they have immunity from prosecution. So, you get a news reporters making stupid statements that first lead the response or lack thereof. The scene is not preserved. As soon as he can get a guy in there to *fix* the problem quietly, he will. This becomes a "spoliation of evidence", which will go badly in court against the owner. However, crucial evidence is lost so the truth becomes subjective rather than objective in many cases.
Let's say you have an incident where some of the flue tile collapsed sufficiently to block the vent connector causing CO to 'leak' into the building. Who's to blame? Well, NFPA 211 calls for annual inspection and maintenance as required as does the IBC. So, any improper installation, defect or deterioration that is passed on from last year is a breech of duty by the building owner. If he failed to provide p.o.s. UL listed CO alarms as required by many codes, then that would be a breech of duty as well. If the owner was properly warned by a service provider of defects but refused to mitigate or correct them, that is a breech of duty and probably gross negligence.
As for the service providers, each one who failed to inspect the chimney is partially at fault, with the last man in being the most at fault. Same for Makeup air, condition of vent connectors, etc. As for performance and combustion analysis, it gets trickier. If the mfr. states to perform CA in his manual then it must be done at commissioning. However, the duty to perform it annually becomes a little more cloudy. CA has not been universally endorsed or required at the national level by industry stds. of care but it has been proven so in court in some individual cases, which can be used against the defendants. Then you have all the mfrs.: appliance, gas controls, gas regulators, gas utility, etc.
So, in such cases, a lot of people may share the blame or "Comparative Negligence" depending upon State laws to apportion blame and financial responsibility.
Until we consolidate our feces, nobody will know who best to call, what local assets are qualified, who pays them and how to initiate their response to the fire ground while the situation is ongoing.
Yeah, they die warm but quickly assume room temperature. Obviously we need to educate a lot of people more about not just the hazards but the incident response process.
@ January 14, 2013 9:45 AM in 150psi press reliefIf the rating tag also indicates it being rated for 210F at 150 psi then it is a temperature/ pressure relief valve such as required on water heaters.
@ January 10, 2013 12:09 AM in Gas heating exhaust extremely loudThe SideShot uses its own proprietary listed vent duct--not single walled galvanized steel vent connector, which is not listed nor approved for positive vent pressure. This unit is adapted to unlisted single walled pipe and that is the misapplication. We can't see the chimney but it certainly is not venting directly through a wall using Tjerlund's duct kit.
@ January 8, 2013 9:14 AM in Gas heating exhaust extremely loudThis is not a sidewall venting application. Look at the installation instructions and literature of a SideShot, as in shooting out the side--not up a chimney. It power vents out a sidewall. Since it is listed as a unit, the entire assembly including the termination are fine. However, adapting this unit to traditional single wall unlisted vent connector is the problem.
@ January 7, 2013 1:54 PM in Gas Boiler and Water Heater Flue / VentingFirst of all, a homeowner should not be doing any work on the venting. This is NOT a DIY project. Hire a pro who is certified in Carbon Monoxide and Combustion Analysis.
From the little bit visible, there are many issues. The venting must be sized properly, connected and supported. That tee in the water heater vent connector serves no purpose other than to introduce too much dilution air into the vent, negate the purpose of a draft hood and provide a convenient place for fumes including carbon monoxide to escape.
The chimney should have a Level II inspection.
@ January 7, 2013 1:25 PM in Gas heating exhaust extremely loudIf this is a SideShot, which is listed for sidewall positive vent pressure but not for adaptation to conventional atmospheric venting, then it is illegal and must be shut down at once. Positive vent pressure venting must be listed to UL 1738. Single walled vent connector is not listed, and gooping the joints and seams is not a recognized modification to meet the listing requirement by the Codes. You can power vent by a device attached on the outside wall or roof termination that sucks the fumes out and is interlocked with the gas controls.
Also, it appears the vent connector reduces, which is not allowed on atmospheric venting. That elbow is not properly supported and is actually sagging downhill, which is not allowed.
@ December 11, 2012 9:48 PM in Does a Stainless Steel Chimney liner need annual cleaning?Most liners I'm familiar with require an annual inspection for maintaining the warranty and sweeping only as required. Solid fuel requires sweeping at least annually, if not monthly depending upon use/ burning characteristics/ etc. Oil requires sweeping when the burner is not properly setup or operating.
Gas fired liners should never require sweeping but should be inspected annually.
@ December 9, 2012 9:59 AM in Schools poisoningsMaybe parents should be sending their kids to school with a relatively inexpensive personal CO alarm clipped onto their school bags. I'm serious. I've personally seen paramedics do this on response to an old lady collapsing at a grocery store and over 20 people went to the ED including 5 to the Hyperbaric Oxygen chamber. This will only be addressed once people get involved. You let a kid take an alarm to school and call you if it goes off then see the firestorm as the school tries to forbid the carrying of a personal alarm and cover that one up.
By touching the boiler in question, they can committed as "spoliation" of evidence. Basically, this means a judge will clobber them and they essentially lose any defense they had. The administrators who ordered this as well as those in charge of mechanical systems and maintenance should lose their jobs, too.